From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755513Ab0FVTqd (ORCPT ); Tue, 22 Jun 2010 15:46:33 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:51322 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755395Ab0FVTqb (ORCPT >); Tue, 22 Jun 2010 15:46:31 -0400 From: Konrad Rzeszutek Wilk To: linux-kernel@vger.kernel.org, fujita.tomonori@lab.ntt.co.jp, iommu@lists.linux-foundation.org, albert_herranz@yahoo.es, x86@kernel.org Cc: Alex Nixon , Jeremy Fitzhardinge , Konrad Rzeszutek Wilk Subject: [PATCH 03/19] xen: Rename the balloon lock Date: Tue, 22 Jun 2010 15:42:36 -0400 Message-Id: <1277235772-26757-4-git-send-email-konrad.wilk@oracle.com> X-Mailer: git-send-email 1.7.0.1 In-Reply-To: <1277235772-26757-1-git-send-email-konrad.wilk@oracle.com> References: <1277235772-26757-1-git-send-email-konrad.wilk@oracle.com> X-Auth-Type: Internal IP X-Source-IP: rcsinet15.oracle.com [148.87.113.117] X-CT-RefId: str=0001.0A090209.4C2112AA.0060:SCFMA4539811,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alex Nixon * xen_create_contiguous_region needs access to the balloon lock to ensure memory doesn't change under its feet, so expose the balloon lock * Change the name of the lock to xen_reservation_lock, to imply it's now less-specific usage. [ Impact: cleanup ] Signed-off-by: Alex Nixon Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/mmu.c | 7 +++++++ drivers/xen/balloon.c | 15 ++++----------- include/xen/interface/memory.h | 8 ++++++++ 3 files changed, 19 insertions(+), 11 deletions(-) diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index a5577f5..9e0d82f 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -70,6 +70,13 @@ #define MMU_UPDATE_HISTO 30 +/* + * Protects atomic reservation decrease/increase against concurrent increases. + * Also protects non-atomic updates of current_pages and driver_pages, and + * balloon lists. + */ +DEFINE_SPINLOCK(xen_reservation_lock); + #ifdef CONFIG_XEN_DEBUG_FS static struct { diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 1a0d8c2..500290b 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -85,13 +85,6 @@ static struct sys_device balloon_sysdev; static int register_balloon(struct sys_device *sysdev); -/* - * Protects atomic reservation decrease/increase against concurrent increases. - * Also protects non-atomic updates of current_pages and driver_pages, and - * balloon lists. - */ -static DEFINE_SPINLOCK(balloon_lock); - static struct balloon_stats balloon_stats; /* We increase/decrease in batches which fit in a page */ @@ -210,7 +203,7 @@ static int increase_reservation(unsigned long nr_pages) if (nr_pages > ARRAY_SIZE(frame_list)) nr_pages = ARRAY_SIZE(frame_list); - spin_lock_irqsave(&balloon_lock, flags); + spin_lock_irqsave(&xen_reservation_lock, flags); page = balloon_first_page(); for (i = 0; i < nr_pages; i++) { @@ -254,7 +247,7 @@ static int increase_reservation(unsigned long nr_pages) balloon_stats.current_pages += rc; out: - spin_unlock_irqrestore(&balloon_lock, flags); + spin_unlock_irqrestore(&xen_reservation_lock, flags); return rc < 0 ? rc : rc != nr_pages; } @@ -299,7 +292,7 @@ static int decrease_reservation(unsigned long nr_pages) kmap_flush_unused(); flush_tlb_all(); - spin_lock_irqsave(&balloon_lock, flags); + spin_lock_irqsave(&xen_reservation_lock, flags); /* No more mappings: invalidate P2M and add to balloon. */ for (i = 0; i < nr_pages; i++) { @@ -315,7 +308,7 @@ static int decrease_reservation(unsigned long nr_pages) balloon_stats.current_pages -= nr_pages; - spin_unlock_irqrestore(&balloon_lock, flags); + spin_unlock_irqrestore(&xen_reservation_lock, flags); return need_sleep; } diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h index af36ead..e6adce6 100644 --- a/include/xen/interface/memory.h +++ b/include/xen/interface/memory.h @@ -9,6 +9,8 @@ #ifndef __XEN_PUBLIC_MEMORY_H__ #define __XEN_PUBLIC_MEMORY_H__ +#include + /* * Increase or decrease the specified domain's memory reservation. Returns a * -ve errcode on failure, or the # extents successfully allocated or freed. @@ -142,4 +144,10 @@ struct xen_translate_gpfn_list { }; DEFINE_GUEST_HANDLE_STRUCT(xen_translate_gpfn_list); + +/* + * Prevent the balloon driver from changing the memory reservation + * during a driver critical region. + */ +extern spinlock_t xen_reservation_lock; #endif /* __XEN_PUBLIC_MEMORY_H__ */ -- 1.7.0.1